Complicated migraine and migraine variants

Episodic migraines in children: limited evidence on preventive pharmacological treatments

The authors conducted a systematic literature review of preventive pharmacological treatments for episodic childhood migraines searching several databases through May 20, 2012. Episodic migraine prevention was examined in 24 publications of randomized controlled trials that enrolled 1578 children in 16 nonrandomized studies. Single randomized controlled trials provided low-strength evidence that propranolol would result in complete cessation of migraine attacks in 713 per 1000 children treated (95% confidence interval, 452-974); trazodone and nimodipine decreased migraine days, while topiramate, divalproex, and clonidine were no more effective than placebo in preventing migraines. Migraine prevention with multidisciplinary drug management was not sustained at 6 months. Divalproex resulted in treatment discontinuation due to adverse effects, and topiramate increased the risk of paresthesia, upper respiratory tract infection, and weight loss. Long-term preventive benefits and improvement in disability and quality of life are unknown. No studies examined quality of life or provided evidence for individualized treatment decisions.

Preventive pharmacologic treatments for episodic migraine in adults

OBJECTIVES

Systematic review of preventive pharmacologic treatments for community-dwelling adults with episodic migraine.

DATA SOURCES

Electronic databases through May 20, 2012.

ELIGIBILITY CRITERIA

English-language randomized controlled trials (RCTs) of preventive drugs compared to placebo or active treatments examining rates of ≥50 % reduction in monthly migraine frequency or improvement in quality of life.

STUDY APPRAISAL AND SYNTHESIS METHODS

We assessed risk of bias and strength of evidence and conducted random effects meta-analyses of absolute risk differences and Bayesian network meta-analysis.

RESULTS

Of 5,244 retrieved references, 215 publications of RCTs provided mostly low-strength evidence because of the risk of bias and imprecision. RCTs examined 59 drugs from 14 drug classes. All approved drugs, including topiramate (9 RCTs), divalproex (3 RCTs), timolol (3 RCTs), and propranolol (4 RCTs); off-label beta blockers metoprolol (4 RCTs), atenolol (1 RCT), nadolol (1 RCT), and acebutolol (1 RCT); angiotensin-converting enzyme inhibitors captopril (1 RCT) and lisinopril (1 RCT); and angiotensin II receptor blocker candesartan (1 RCT), outperformed placebo in reducing monthly migraine frequency by ≥50 % in 200-400 patients per 1,000 treated. Adverse effects leading to treatment discontinuation (68 RCTs) were greater with topiramate, off-label antiepileptics, and antidepressants than with placebo. Limited direct evidence as well as frequentist and exploratory network Bayesian meta-analysis showed no statistically significant differences in benefits between approved drugs. Off-label angiotensin-inhibiting drugs and beta-blockers were most effective and tolerable for episodic migraine prevention.

LIMITATIONS

We did not quantify reporting bias or contact principal investigators regarding unpublished trials.

CONCLUSIONS

Approved drugs prevented episodic migraine frequency by ≥50 % with no statistically significant difference between them. Exploratory network meta-analysis suggested that off-label angiotensin-inhibiting drugs and beta-blockers had favorable benefit-to-harm ratios. Evidence is lacking for long-term effects of drug treatments (i.e., trials of more than 3 months duration), especially for quality of life.